Quincy Medical Center remained open for business Thursday as hundreds of nurses walked the picket line during a 24-hour strike that began at 6 a.m.

Nurses say they are trying to highlight what they describe as unsafe patient conditions in the hospital. Meanwhile, hospital officials call that description false and say the strike won’t affect ongoing contract negotiations.

“We’re taking care of too many patients,” said Kristin Conneely of Hull, a nurse in Quincy for 11 years who was walking the picket line in front of the hospital on Whitwell Street at about 7 a.m. Thursday.

The strike is scheduled to end at 6 a.m. Friday.

Inside the hospital Thursday, Quincy Medical Center President Daniel Knell said some of the 236 nurses on staff chose to work despite the strike. He would not say how many.

He added that the hospital will be fully staffed throughout the strike with physicians, technicians and replacement nurses. About an hour after the strike began, Knell escorted a Patriot Ledger reporter to the nurses’ stations in the emergency department and on a surgical floor. Both areas appeared to be staffed.

A man dressed in a hospital gown sat in a wheelchair in the hallway on the surgical floor and monitors from the state Department of Public Health were also visible inside the hospital.

Knell said the hospital offered the union “generous” early retirement and severance packages, including five years of health insurance coverage, to fend off the strike, “and they chose not to take it.”

State Sen. John Keenan, D-Quincy, visited the picket line Thursday morning and said he was there to "show support for the nurses and encourage both sides to get back to the negotiating table."

U.S. Rep. Stephen Lynch, the South Boston Democrat running in the special election for U.S. Senate, was expected to join a rally in support of the nurses' union at noon.

Nurses from other Steward-owned hospitals, including Morton Hospital in Taunton, Norwood Hospital and Holy Family Hospital in Metheun, joined the picket line during the first few hours of the strike Thursday morning and a rally was scheduled for noon. Nurses from Brigham and Women's, Boston Medical Center and Faulkner Hospital were expected to join the Quincy picket line later in the day, Quincy emergency department nurse Stacey McEachern said.

Steward bought the Quincy hospital in Oct. 2011 for $38 million. The purchase in bankruptcy court required a new contract to be negotiated with nurses. While they initially voiced optimism about Steward’s arrival, nurses have mostly expressed dissatisfaction with the tenor of negotiations.

The nurses strike is the first in Quincy Medical Center’s history and the first in Greater Boston in 25 years.

A key negotiation sticking point is staffing ratios for different units in the hospital. The union wants to reduce the number of patients that can be assigned to individual nurses at a given time. Steward says current staffing levels are sufficient considering patient volumes.

Page 2 of 2 - On the picket line, nurses disagreed and described being forced to “float” between departments, taking care of patients they don’t have the training for.

Evelyn Kelleher of Braintree, a nurse for 17 years, said that nurses who take their concerns about understaffing to hospital managers are routinely told: “Do the best you can, we’ll get through it.”

Knell called claims about the quality of care at the hospital false. “This strike will have a negative impact on Quincy Medical Center’s finances and the false public statements about our quality, made by our own nurses, jeopardizes the community’s confidence in our ability to care for them,” he said.

Steward is a Boston-based for-profit company launched by private-equity firm Cerberus Capital Management in 2010 to buy the six hospitals in the Caritas Christi System. That group includes Norwood Hospital, Carney Hospital in Dorchester and Good Samaritan Medical Center in Brockton. Steward also owns New England Sinai Hospital in Stoughton and Morton Hospital.

A few hours after the strike began Thursday morning, the Massachusetts Nurses Association took aim at the private-equity firm by erecting a large inflatable figure of Cerberus, the three-headed "hellhound" of Greak and Roman mythology, in a yard across the street from the hospital.

Steward countered with a pair of trucks both carrying large billboards with "The Future of Health Care is in Quincy," on one side and "But the MNA is Living in the Past," on the other. The trucks were being regularly driven by the striking nurses.

On Wednesday, hospital management reviewed the contingency plans and processes they will adhere to during the strike, Steward spokesman Christopher Murphy said.

“We want to make sure that, for the patients that are in the hospital and the patients that come (Thursday), any disruption is minimized if not eliminated, and all the employees know what’s happening and if there are any changes to their routine,” he said.

The hospital postponed elective surgeries because of the strike, and contacted patients in the last few days to reschedule, Murphy said.

Nurses spent Wednesday finalizing schedules to ensure there is 24-hour picketing at the hospital and nailing down logistics, supplies, and travel for supporters.